Main Findings
Our study found that APH in the setting of PP has significant
implications for mothers intraoperatively and postpartum, including a
tendency for preterm emergency caesarean sections under general
anaesthesia, with greater blood loss requiring transfusion, and longer
postpartum stay.
The incidence of PP in our population was 0.8%, compared to the
incidence reported in the current literature at
0.2–0.4%.8,15 This is likely due to the large number
of high-risk obstetric referrals received at the study hospital known to
be a major tertiary centre.
In our study, the majority (62%) of women with placenta praevia
experienced antenatal haemorrhage, which is consistent with a previous
study14 and slightly greater than reported (51.6%)
within the systematic review and meta-analysis of twenty-nine articles
with 4687 individuals by Fan et al.6 Despite excluding
all placenta accreta cases, our study examines the largest number of
women diagnosed solely with placenta praevia compared to any previous
individual article noted by Fan et al.6
We found that maternal characteristics, though may predispose a
diagnosis of placenta praevia, made no difference in risk of antepartum
bleeding in women with placenta praevia, alike a prior study by
Mastrolia et al.16 However, the diagnosis of major PP
significantly increases the risk of APH (OR 2.88p <0.001) compared to minor PP. This result is supported
by another large retrospective cohort of 306 women by Bahar et
al.17 (OR 3.18, 95% CI 1.58–6.4, p =0.001) and
similarly reported in a population of 121 women by Bhide et
al.18 comparing APH in major versus minor PP (57.1%
versus 47.5% p <0.05). Besides the degree of PP,
developing research suggests that the likelihood of APH might also be
related to the placental edge thickness19 and
echo-free space in the lower edge of the placenta.20
The increased risk of preterm delivery in women with PP is well
established.21,22 In our study, women with PP who
experienced bleeding were significantly more likely to deliver earlier
than those without bleeding (median 35.4 versus 38.0 weeks,p <0.001). This finding is consistent with results by
Lam et al.,14 who also found that newborns delivered
from mothers with APH were smaller and more frequently required nursery
admission. Therefore the earlier timing of delivery in placenta praevia
seems to correlate with the incident of at least one bleeding episode
and degree of PP, which in itself increases the tendency to bleed.
Pivano et al.23 published a scoring system that
predicted the risk of emergency caesarean for women with placenta
praevia based on the type of PP, frequency and intensity of antenatal
bleeding and gestational age at sentinel bleed. In our population, women
who had experienced APH were more likely to undergo an emergency
caesarean sections than their asymptomatic counterparts for lower
uterine segment (61% vs 25%) and classical incisions (8.5% vs 1.4%),
which correlates well with significant findings by Love et
al.24 (63% vs 25% p <0.001) and
Fishman et al.25 (OR 17.7 95% CI 6.1–51.7).
Interestingly, in our study there was a novel finding of three-fold
increased risk of undergoing general anaesthesia in women with bleeding
that has not been reported before in the literature. This might be
explained by the urgency of delivery as suggested by earlier gestations
and greater proportion of emergency caesareans in the antepartum
bleeding cohort. The use of general anaesthesia in caesarean sections is
associated with a greater volume of blood loss than neuroaxial
anaesthesia.26
We found that both syntocinon bolus and infusions were used more
frequently intra-operatively in situations where bleeding had occurred.
Otherwise, there was no difference in the median number of uterotonics
used between the compared cohorts. Likewise, besides use of surgicell
(OR 3.56, 95% CI 1.45–8.73) and Bakri balloon (OR 10.3, 95% CI
1.35–78.2), there were no differences in additional surgical techniques
required for managing bleeding in the APH group versus those without
APH. A plausible explanation for the lack of statistical significance in
both medical and additional surgical techniques, including hysterectomy,
might be the heterogeneity of surgical and anaesthetic experience and
individual preferences within the study hospital, which may range from
junior obstetric trainees to skilled specialists.
Women with PP who bled antenatally were likely to have significantly
greater volume of blood loss postoperatively than their asymptomatic
counterparts (IRR 1.20, 95% CI 1.05–1.37), requiring over three-fold
the number of blood transfusions. Mastrolia et al.16similarly found a tendency for blood transfusions in the presence of
APH, unlike previous studies.14,24
Besides a marginally longer postpartum hospital stay for those who
experienced APH, there was no difference in postoperative complications.
The current literature has scarcely focused on postpartum maternal
outcomes in PP,27,28 and for those that have evaluated
this aspect have also found no significant difference between the
presence and absence of APH.14